Method and apparatus for developing and drying motion picture film



Oct. 31, 1933. F. B. THOMPSON 1,933,127

METHOD AND APPARATUS FOR DEVELOPING AND DRYING MOTION PICTURE FILM Filed March 3]., 1951 4 Sheets-Sheet l gM/M Erna/avg).

19331 F. B. THOMPSON METHOD AND APPARATUS FOR'DEVELOPING AND DRYING MOTION PICTURE FILM Filed March 31, 1951 4 Sheets-Sheet 2 0 H w M a 3 J I J M 00 F ilig O 8 v w 4 J 4 I, fi 7 A I; 6 1 x a. 7 m 1 4 4T m. h .m 7 z\ -1 "r u o J M r a R "I I" lullrr 7 n Oct. 31, 1933. F. B. THOMPSON METHOD AND APPARATUS'FOR DEVELOPING AND DRYING MOTION PICTURE FILM Filed March 31, 1931 4 Sheets-Sheet I5 1% sewn E Flo/vase Oct. 31, 1933. F. B. THQMPSON METHOD AND APPARATUS FOR DEVELOPING AND DRYING MOTION PICTURE FILM Filed March 51, 1931 4 Sheets-Sheet 4 Patented Oct. 31, 1933 UNITED STATES METHOD AND APPARATUS FOR DEVELOP- ING AND DRYING MOTION PICTURE FILM Frederick B. Thompson, Hollywood, Calif.

Application March 31, 1931. Serial No. 526,600

15 Claims.

This invention has to do, in a general way, with the treatment of photographic film, and is more particularly related to a method and apparatus for developing, fixing, washing, and drying motion picture film.

The invention has as one object the production of an apparatus for developing and drying film which is of simple form and construction, and in which the film is moved in a manner such that it is not injured by the film-moving mechamsm.

The invention has as a further object the production of an improved method for drying mo- W tion picture film; such a method being designed to improve the quality of the film; reduce the time required for the drying operation; and also reduce the space occupied by the film drying apparatus.

It is well known, by those familiar with the art, that the usual construction followed in developing machines comprises a plurality of tanks, each of which contains a series of top and bottom rollers over which the film is wound in a spiral or helical path. In an apparatus of this character, the film engages the rollers at an angle so that its edges are in contact with the flanges on the ends of the rollers. This has a tendency to wear the edges of the film, and where the driving rollers are in the form of sprockets adapted to engage the perforations in the film, there is a tendency for the perforations to be torn, due to this angular relation between the film and the rollers.

Also, in developing machines where the film is carried through the various baths in a spiralpath, the movement of the film tends to set up a swirl or eddy. in the bath so that the solution, which originally contacts the film, has a tendency to be drawn clear through the bath with that portion of the film which it originally contacts.

It is a noteworthy feature of the machine contemplated by this invention that the film travels from one roller to the next roller'in a straight line path. In other words, the top and bottom rollers are situated in vertically spaced relation with each other, and in the same plane, so that the film is not drawn sideways across the flanges of the rollers.

It is another feature of the machine contemplated by this invention that the film is moved through the various baths in a manner such that no swirl or eddy can be set up, due to the movement of the film. These features are accomplished by making the top rollers, over which the film passes, and which incidentally are the film driving rollers, of a relatively large diameter, and placing below these rollers, near the bottom of the tanks, a series of loop-maintaining rollers over which the film passes. These loop-maintaining rollers are constructed and arranged so as to maintain the film in a plurality of independent loops which are suspended on each side of the top-driven rollers, and in which the film moves in opposite directions in the successive loops.

In a preferred form of my invention, I provide, in addition to the two sets of rollers mentioned above, a series of film guide rollers, which are situated between the driven rollers and the loop maintaining rollers, and are provided for the purpose of guiding the film from one loopmaintaining roller to the next loop maintaining roller. In a machine of this character it will be apparent that the successive rollers in the film-supporting series must be driven in opposite directions, and in this connection I provide a machine with novel means for driving the rollers in this manner, such means incidentally forming a support for the film-supporting rollers.

In the operation of a machine of the class described, it is sometimes necessary to render the film-supporting or film-driving rollers inoperative so as to take up any slack which may have developed in the developing unit. I consider it a further object of this invention therefore to provide the machine with means for disengaging the film-supporting or film-driving rollers from the driving means.

The usual construction followed in film drying units for use in connection with a film-treating apparatus of the class described, embodies a large closed chamber through which the film is moved in a tortuous path, and through which properly conditioned air is circulated. The film, after it leaves the washing tanks, is led directly to this drying chamber, and the' chamber must be of a size such that the film is perfectly dry when-it is removed therefrom. Chambers of this character are always quite large, and, obviously, occupy considerable space as compared with the drying apparatus contemplated by this invention.

As pointed out above, this invention contemplates 9, novel method of drying motion picture film. In carrying out this method I first pass the film, after it leaves the washing unit, through a volatile solution wherein the water on the film is replaced by the volatile liquid. After passing through this liquid, or solution, the film is subjected to the action of an air jet, or a plurality of air jets, which are effective to almost instantaneously dry the film. By treating the film in this manner I have found that the finished product is superior to that produced in the usual type of film-drying apparatus. The film does not have an opportunity to become brittle, and this method of drying prevents the contraction of the film and the consequent cracking of the emulsion. In film carrying a sound track, I have found that this method of drying gives a sharper sound track and a consequent purer tone in its reproduction. The dried film is more flexible than that dried by the ordinary method, and, consequently, has a longer life.

The details in the construction of a preferred form of by invention, together with other objects attending its production, will be best understood from the following description of the accompanying drawings which are chosen for illustrative purposes only, and in which- Fig. 1 is an elevational view showing a preferred form of film treating apparatus contemplated by this invention;

Fig. 2 is an enlarged sectional elevation taken in aplane represented by the line 2-2 in Fig. 1;

Fig. 3 is a sectional elevation taken in the plane represented by the line 3-3 of Fig. 2;

Fig. 4 is a sectional elevation illustrating de tails in the construction of the preferred drying unit contemplated by this invention;

Fig. 5 is an inverted plan view taken in the plane represented by the line 5-5 of Fig. 4; and

Fig. 6 is a fragmentary sectional elevation illustrating a preferred form of driving connection employed in the film developing unit.

Referring more particularly to the drawings:

The film-treating apparatus is shown as comprising a developing, fixing, and washing unit, indicated at A, and a film-drying unit, indicated generally by reference character 13.

The unit A comprises a plurality of tanks or receptacles embodying a developing tank 11, a rinsing tank 12, a fixing tank 13, and washing tanks 14. The film indicated at F passes through each of these tanks and over a guide roller 18 to the firm-drying unit B. The drying unit B consists in a general way of a tank 19 which contains a volatile liquid, such as gasoline or a mixture consisting of 95% alcohol, 4% glycerol, and 1% glacial acetic acid. This liquid replaces the water on the film, and due to its volatile character is readily removed by air jets which are embodied in the drier, indicated by reference numeral 20. I have also found that the latter solution has a curing effect upon the film which greatly improves the quality of the finished film.

Reference numeral 21 indicates a frame which consists of standards 22, 23, and 24, and a beam 25. This frame forms a support for the shafts and source of power used in driving the film, and also comprises a support for the means employed in lifting the film-driving mechanism from the tanks. This last mentioned mechanism is supported in the various tanks by means of rails 30 and 30', which extend throughout the length of the various tanks, and which are flanged in a manner such that the flanged portions rest upon the edges of the tanks.

The construction of a preferred form of filmdriving unit is best illustrated in Figs. 2 and 3, where it will be noted that a pair of end plates 31 and 32 are secured between the rails 30 and 30, near the ends of the tank indicated by reference numeral 13. These end plates are preferably made of bakelite, or some other suitable material, and are constructed so as to extend an appreciable distance down into the solution contained in the tank.

Reference numerals 33 and 34 indicate standards which project downwardly from the end plates and terminate in "r-mernbers 35 and 36, near the bottom of the tank.

Reference numeral 37 indicates a transverse beam, or bar, which is interposed between the lower ends of the plate members 31 and 32.

The two end plates 31 and 32 are provided at their midportions with slots indicated by reference numerals 38, and these slots receive the two end portions of a shaft 39 whichfis held against transverse movement in the slots by means of collars 40. Rotatably mounted upon the shaft 39 are a, plurality of film-supporting rollers, indicated by reference numerals 41 and 41'. These rollers have their lower surfaces in engagement with a pair of secondary rollers 42 and 42', which, in turn, are mounted on two parallel shafts 43 and '43. The shafts 43 and 43' are supported in bearings 44 in the end plates 31 and 32, and have their outer end portions provided with gears rlndicated at 46, which are in engagement so that the two shafts, when one of them is rotated, will be revolved in opposite directions.

In order that the secondary rollers (42, 42), which support the film-supporting rollers 41 and 41', may be effective to drive the successive rollers 41 and 41 in the series of film-supporting rollers in opposite directions, I key alternate secondary rollers to the respective drive shafts 43 and 43. In other words, where one of the rollers 42 is keyed to its shaft 43, the corresponding roller 42 is idle on the shaft 43; similarly, when a roller 42 on the shaft 43 is idle, the corresponding roller 42 is keyed' to the shaft 43. In this manner, the successive film-supporting rollers are driven in opposite directions.

For the purpose of driving the shafts 43 and 43', I provide one of the shafts (43) with a miter gear 47, which is engaged by a gear 47 mounted on the lower end of an angularly disposed auxiliary shaft 48. The shaft 48 is journaled in bearings 49 and 50, which are mounted on the end plate and has its upper end portion provided with a miter gear 51, which engages a gear 52 mounted 011 the shaft 53. The shaft 53 extends longitudinally throughout the length of the entire unit A and has its bearings in the various end plates, exemplified by reference numerals 31 and 32.

The shaft 53 is driven through the medium of gears 56 and 57 from a vertical drive shaft 58, which has its lower end in a thrust bearing 59. and is provided with a bearing 60 at its midportion, such bearing being secured to the end of the last tank in the series. The upper end of shaft 58 is journaled in a bearing 61 on the beam 25, and is driven through gears 62 from a motor and reduction gear unit, indicated generally by reference numeral 63 and a shaft 64.

In order that the film-supporting units may be lifted from the various tanks. I show the gear 5'7 as being mounted in a bearing 66 which is secured to a bracket 67, the bracket, in turn, being mounted on the longitudinal rail 30. This construction is best illustrated in Fig. 6.

Returning to Figs. 2 and 3. it will be noted that T-members 35 and 36 support a pair of parallel shafts '70 and '71, the end portions of which are received in slots formed in the T- members, and are held against transverse move ment therein by means of collars 72. Each of these shafts carries a plurality of idle rollers 73 and 74 which are situated directly beneath the various film-supporting rollers 41 and 41, and are arranged so that the film F, in passing over the rollers 41 and 41, is suspended from the opposite sides of these rollers in independent loops. The transverse bar, or beam, 37, is provided on opposite sides with film guide rollers '75 and '76 which are employed for the purpose of guiding the film from one of the loop-maintaining rollers 73 or 74 to the next successive loop-maintaining roller.

Following the course of the film as illustrated in Figs. 2 and 3, it will be noted that the film enters the tank over a guide roller 80, which is mounted on a bracket 81 secured to the rail 30. After passing over this roller, the film is led downwardly, and is twisted through so that it finally passes under the first loop-maintaining roller '74 on the shaft 70. Leaving this roller, the film is led upwardly and twisted through 90 so as to pass over the first guide roller '16, which is rotatably mounted on the transverse beam 37. It is preferable that these guide rollers are so formed and so arranged that their two oppositefilm-engaging surfaces are in alignment with the central portions of the loop-maintaining rollers situated therebelow. The film, after leaving the first guide roller, is twisted through 90, and passes downwardly under the next loopmaintaining roller in the series, after which it is led up to and over the first film-supporting roller 41. The film then passes downwardly over the opposite side of the film-supporting roller, and under the next loop-maintaining roller from which it is led upwardly and twisted to pass over the next guide roller, thence downward and under the next loop-maintaining roller, and so on throughout the series until it passes under the final loop-maintaining roller '73 from which it is led upwardly and twisted through 90 to pass over the final guide roller 83, which is similar to the guide roller 80, being mounted on a bracket 84 which is secured to the rail 30.

After passing over the roller 83, the film then enters the next tank in the series, or in the event of the last tank, is drawn upwardly over the roller 18 prior to its introduction into the tank 19.

It was pointed out in the fore part of the specification, as one feature of this invention, that means were provided for disengaging the film supporting means and their corresponding driving means. Such means are shown as comprising an upright rod, or bar, 86, which extends through the shaft 39, and is provided with engaging nuts 87 situated below the shaft. This bar 86 has its upper end extending through an eye 88 formed on a lever member 89 and is held against downward movement relative to the lever member by means of a nut 90. The lever member 89 is mounted on a screw or pin 91, which extends through or is threaded into a hub 92 formed in the end plate, and it will be noted from Fig. 2 that the lever member, or lever members, have projecting tongues 93 which are adapted to be engaged by a cam member, or cam members, 94, secured to a shaft 95 which is supported by bearing brackets 95' mounted on the rail 30' and which is adapted to be operated by an operating lever or a plurality of such levers 94; This construction may be employed at each of the end plates so that b roller-supporting shaft may be lifted by an operator situated at any point along the unit A,

and it will be observed that when the cam or cams 94 are rotated in the general direction of the arrow C, and that the cam members are effective to press the tongue on the lever member downwardly, thus lifting the shaft 39 so that the rollers 41, 41' are out of engagement with the driving rollers 42 and 42'.

For the purpose of lifting the film-driving mechanism from the tanks to thread the film, or to change the solution in the tanks, I provide connecting means which may be in the form of eye bolts situated at spaced points between the rails 30 and 30'. These connecting means are secured to the lower end portion of cables 101 which pass upwardly over pulleys 102 mounted on the beam 25, and over a guide pulley, or guide pulleys 103, to weights 104. The weights are constructed so as to facilitate a lifting of the film-driving mechanism from the tanks, and means may be provided for holding the units in elevated position after they have been lifted.

As pointed out above, the film-drying unit embodies a tank 19, the construction of which is best illustrated in Fig. 4, where it is shown as being provided with a cover member 110, which has film inlet and film outlet openings 111 and 112, respectively. These inlet and outlet openings are provided with pressure rollers which are adapted to engage the film F as it passes therethrough, such rollers being indicated by reference numerals 113, 113', 114 and 114. These rollers serve to provide a seal in the tank 19 which will prevent the escape of the vapors from the tank. The film is lead into the tank over a guide roller 115, and is guided through the tank in a tortuous path by means of rollers 116 and 117, which are mounted between bars 118 and 119.

The film leaving the tank 19 passes over a guide roller 120, which is shown as being mounted upon the top cover, and over a second guide roller 121, which is mounted on a shaft 122 secured to the side member 123 of a hood 124.

The hood 124 forms a part of the drier 20, which is shown as comprising standards 125 and 126. The upper ends of the standards 125 and 126 support a shaft 127 on which a plurality of film-guiding wheels 128 and 128 are rotatably mounted. These wheels 128 and 128' have their lower portions in engagement with oppositely disposed driving rollers 129 and 129, which, in turn, are supported on drive shaft 130 and 130. These driving rollers 129 and 129, like the rollers shown in Figs. 2 and 3, are alternately driven and idle, and the arrangement of the rollers is such that the successive film-supporting wheels 128 and 128 are driven in opposite directions.

The film F passing over the first film-supporting wheel 128 is led downwardly and is twisted through 90 so as to pass below the film guide roller 140, which is rotatably mounted on a bracket 141, shown as being secured to the floor, or base, of the drier. After passing over this roller, the film is then led upwardly and passes over the next film-supporting wheel 128', after which it is led down to a corresponding guide roller 140', which is mounted upon a bracket 141', secured to the base of the drier on the side opposite the roller and brackets 140 and 141.

The shaft 130' is driven through the medium of gears 133 from an upright shaft 134, which, in turn, is geared to the shaft 64, and the shaft 130 is driven by means of gears 136, which, in turn, are driven from a chain 137 which passes over a sprocket wheel 138 mounted on the end of shaft 130'. In this manner the two shafts 130 and 130' are driven in opposite directions.

During the movement of the film over the filmsupporting wheels 128 and 128, etc., it is subjected to the action of a plurality of air jets which come from nozzles 143 mounted on the hood memher 124, the air preferably being heated for the most efficient drying effect. The film is finally led from the drier over the guide roller 145 to a suitable receptacle, or a take-up reel, not shown.

With regard to the take-up mechanism and the drive for the film, it is pointed out that the film supporting rollers are made of a diameter such that the surface is great enough to provide sulficient friction between each roller and the film, to drive the portion of the film suspended from that rollers so that it is unnecessary to maintain the film under tension by a frictionally driven take-up reel nor is it necessary to provide the machine with driven sprocket rollers at various points to maintain the film in motion.

From the foregoing description it will be observed that my invention embodies novel means for supporting and moving the film which, in its broader aspect, comprises a series of film suppoiting and moving units adapted to support the film in a plurality of independent loops suspended from each side of the successive film supporting units, and associated with means for driving the successive units in the series in opposite directions. These units may comprise the series of rollers 41. and 41' (Fig. 3), the wheels 128 and 128 (Fig. 5), or each unit may be comprised of two or more parallel rollers one or more of which is driven in one direction and one or more of which is idle. These latter units are arranged in series and the driven rollers in each successive unit are driven in opposite directions.

It will also be apparent from the foregoing description that the device contemplated by this invention is of simple form and construction. it occupies a very small space as compared with the ordinary type of filnitreating apparatus, and the invention embodies a novel method of drying film which is, of course, not confined to the particular type of apparatus shown.

It is to be understood that while I have herein described and illustrated one preferred form of my invention, the invention is not limited to the precise construction described above, but includes within its scope whatever changes fairly come within the spirit of the appended claims.

I claim as my invention:

1. In a film treating apparatus, film moving means embodying: a series of driven film supporting rollers arranged to rotate in substantially parallel vertical planes and spaced apart along a transverse vertical plane, said rollers being adapted to support a film in independent loops which are suspended from opposite sides of each of said rollers; means for rotatably supporting said rollers; and means for driving the successive rollers in said series in opposite directions.

2. In a film treating apparatus, film moving means embodying: a series of driven film supporting rollers adapted to support a film in independent loops which are suspended from opposite sides of each of said rollers; means for rotatably supporting said rollers in substantially coaxial relation with each other; and means for driving the successive rollers in said series in opposite directions.

3. In a film treating apparatus, film moving means embodying: a series of driven film supporting rollers arranged to rotate in substantially parallel vertical planes and spaced apart along a transverse vertical plane, said rollers being adapted to support a film in independent loops which are suspended from opposite sides of each of said rollers; means for rotatably supporting said rollers; means situated below said driven rollers on opposite sides thereof for engaging said film and maintaining the loops therein; and means for driving the successive rollers in said series in opposite directions.

4. In a film treating apparatus, film moving means embodying: a series of driven film supporting rollers arranged to rotate in substantially parallel vertical planes and spaced apart along a transverse vertical plane, said rollers being adapted to support a film in independent loops which are suspended from opposite sides of each of said rollers; means for rotatably supporting said rollers; roller means situated vertically below said driven rollers and on opposite sides thereof for engaging said film and maintaining the loops therein; and means for driving the successive rollers in said series in opposite directions.

5. In a film treating apparatus, film moving means embodying: a series of driven film supporting rollers adapted to support a film in inde pendent loops which are suspended from opposite sides of each of said rollers; means for rotatably supporting said rollers; roller means situated vertically below said driven rollers for engaging said film and maintaining the loops therein; film directing rollers situated between the driven rollers and the loop maintaining rollers for guiding the path of said film from one loop maintaining roller to the next loop maintaining roller; and means for driving the successive ro1lers in said series in opposite directions.

6. In a film treating apparatus, film moving means embodying: a shaft; a series of rollers rotatably mounted on said shaft and adapted to support a film in a series of independent loops which are suspended from opposite sides of said rollers; and means for driving the successive rollers in said series in opposite directions.

7. In a film treating apparatus, film moving means embodying: a shaft; a series of rollers r0- tatably mounted on said shaft and adapted to support a film in a series of independent loops which are suspended from opposite sides of said rollers; and means for driving the successive rollers in said series in opposite directions, said last mentioned mean comprising a pair of parallel shafts rotatably mounted below said rollers, means for driving said shafts in opposite directions, and driven rollers on said shafts engaging alternate film supporting rollers.

8. In a film treating apparatus, film moving means embodying: a shaft; a series of rollers rotatably mounted on said shaft and adapted to support a film in a series of independent loops which are suspended from opposite sides of said rollers; and means for driving the successive ro1lers in said series in opposite directions, said last mentioned means comprising a pair of parallel shafts rotatably mounted below said film supporting rollers, means for driving said shafts in opposite directions, and a series of successive idle and driven rollers mounted on said shafts in engagement with said film supporting rollers, said last mentioned rollers being arranged so that a driven roller on one driven shaft drives a film supporting roller which is engaged by an idle roller on the other driven shaft.

9. In a film treating apparatus, film moving means embodying: a shaft; a series of film supporting rollers rotatably mounted on said shaft; a pair of driven shafts rotatably supported below said film supporting rollers; means for driving said driven shafts in opposite directions; alternate driven and idle rollers mounted on said driven shafts in engagement with said film supporting rollers for driving the successive film supporting rollers in opposite directions; and means for optionally lifting said film supporting rollers out of engagement with said driven and idle rollers.

10. In a film treating apparatus, film moving means embodying: a shaft; a series of film supporting rollers rotatably mounted on said shaft; a pair of driven shafts rotatably supported below said film supporting rollers; means for driving said driven shafts in opposite directions; and alternate driven and idle rollers mounted on said driven shafts in engagement with said film supporting rollers for driving the successive film supporting rollers in opposite directions.

11. In a film treating apparatus, film moving means embodying: a frame comprising longitudinal supporting bars, end plates, and standards projecting downwardly from said end plates; a roller carrying shaft having its end portions mounted in said end plates; a series of film sup porting rollers rotatably mounted on said roller supporting shaft; a pair of drive shafts mounted in said end plates below said film supporting rollers; alternate driven and idle rollers mounted on said drive shafts in engagement with said film supporting rollers and arranged to drive the successive film supporting rollers in said series in opposite directions; a pair of shafts mounted between the lower ends of said standards in substantial alignment with opposite sides of said film supporting rollers; and film loop maintaining rollers on said shafts.

12. In a film treating apparatus, a film moving means embodying: a frame comprising longitudinal supporting bars, end plates, and stand ards projecting downwardly from said end plates; a roller carrying shaft having its end portions mounted in said end plates; a series of film supporting rollers rotatably mounted on said roller supporting shaft; a pair of drive shafts mounted in said end plates below said film supporting rollers; alternate driven and idle rollers mounted on said drive shafts in engagement with said film supporting rollers and arranged to drive the successive film supporting rollers in said series in opposite directions; a pair of shafts mounted between the lower ends of-said standards in substantial alignment with opposite sides of said film supporting rollers; film loop maintaining rollers on said shafts; a cross member mounted in said frame below said film supporting rollers; and film guide rollers mounted on said cross member for guiding said film between successive loop maintaining rollers.

13. In a film treating apparatus, means for supporting and driving a film embodying: a series of film supporting and driving rollers arranged transversely with the general direction of travel of said film and spaced apart along the general direction of travel of said film, said rollers being adapted to support said film in independent loops which are suspended from opposite sides of said supporting rollers, and means for driving the successive film supporting rollers in said series in opposite directions.

14. In a film treating unit, means for supporting and driving a film embodying: rollers spaced apart throughout the length of said unit to form a series; and means for driving the successive rollers in said series in opposite directions.

15. In a film treating unit, means for supporting and driving a film embodying: rollers spaced apart throughout the length of said unit to form a series; means for maintaining a loop of film on each side of each roller; and means for driving the successive rollers in said series in opposite directions.

FREDERICK B. THOMPSON 

